Self-optimizing symbology reader

ABSTRACT

The present invention provides a method to optimize the configuration of a symbology reader without the need for user intervention. Following a predetermined number of successful decodes, the reader automatically determines the symbology of interest and disables the decoding algorithms not being used. For example, if after four or five successful decodes have occurred and the unit determines that all of the successful decodes were of a single symbology type such as a PDF417 barcode, all other decoding algorithms, with the exception of the PDF417 decoder, will be disabled. Other embodiments may be included which adjust the scan window size and the image capture parameters of the reader based on the symbology of interest.

FIELD OF INVENTION

The present invention relates generally to symbology readers, and moreparticularly to a method for automatically optimizing the configurationof a symbology reader.

BACKGROUND OF THE INVENTION

Barcode readers, including scanners, symbology readers and imagereaders, are typically supplied with a wide range of decoding algorithmsactive within the operating software. Present-day barcode or opticalcharacter decoders are usually software algorithms which analyze thesignal or image obtained by the barcode reader and decipher theinformation encoded in the barcode symbology. The decoded data is thenstored for later processing or forwarded to a microprocessor. As themanufacturer of these barcode readers often cannot tell in advance howthe device is to be used, the full range of common symbologies,generally one dimensional and two dimensional barcodes, as well aspostal codes and optical character fonts are typically supported andtheir decoding algorithms are enabled for decoding at all times.

Further, in image-based readers, a large field of view is often thedefault state, as again, the manufacturer cannot determine in advancethe intended application. The symbologies can range from large,multi-code labels where the full field of view is both desired andnecessary, to small barcodes that occupy significantly less of the totalarea capture in each scan.

There are a number of prior art techniques in which a category of decodealgorithms may be selected from a menu. The driver for selecting a groupor even a single decoding algorithm in a device to reduce the timerequired to successfully determine the existence of a symbology,deciphers the coded information and passes this information to someexternal information management system, thereby maximizing operatingproductivity. Generally, the selection of categories would includeeither one-dimensional or two-dimensional barcodes, postal codes oroptical characters. One-dimensional barcodes are barcodes in which thedata is encoded along a single axis. One-dimensional barcodes arecommonly used in grocery stores and other retail applications. UPC/EANcode, Code 39 and Code 49 are all examples of one-dimensional barcodes.Two-dimensional barcodes are barcodes in which data is encoded in boththe horizontal and vertical dimensions. PDF417 and maxicode are examplesof two-dimensional barcodes. Postal codes ressemble one-dimensionalbarcodes. POSTNET, PLANET and Royal Mail 4 state are examples of postcodes. Optical characters are typically OCR A and OCR B font—typicallyused for machine read applications.

In these menu driven barcode readers, an operator would select betweenone or more of the available barcode options depending on the symbologytype of interest. For example, if the one-dimensional option isselected, the two dimensional decoding algorithms are typicallydisabled. The main drawback to this type of system is that it requiresoperator intervention in order to select the decode parameters. For thisoperator intervention to be effective the user must be capable ofdifferentiating between the myriad of codes, often something theoperator is not able to do.

U.S. Pat. No. 5,825,006 which issued to Longacre, Jr. et al on Oct. 20,1998 and is assigned to Welch Allyn, Inc., details a menu driven barcodereader having improved auto discrimination features. The system refersto a parameter table in memory during the decode operation to autodiscriminate between 1D and 2D barcode types. If a 1D barcode is beingscanned, all 2D barcode decoding algorithms are disabled. While thissystem does partially optimize the operation of the bar code reader bydisabling all algorithms relating to a broad category of decodealgorithms not being used, it does have the drawback of not disablingall unused decode routines. Further, this system does not include afeature with image-based readers, whereby the field of view (FOV) orother optical operating parameters can be adjusted to accommodate thearea or dimensions of the symbology of interest. These menu-drivenbarcode readers can be configured either through the use of a host-basedmenu, or the use of what is known in the industry as configurationbarcodes. These barcodes contain the instructions to set the device intoa specific operating mode. If the end user desires to alternate betweena series of modes, configuration barcodes must be created and beavailable at the point of use to allow the user to change the operatingparameters of the device by successfully decoding the instruction set inthe barcode.

Other products available to barcode users, including portable dataterminal devices such as the Symbol Technologies PDT8100™ or the HandHeld Product Dolphin 9500™, utilize a screen-driven menu in which a usercan select a symbology or symbologies of interest, however, thisrequires the user to be able to anticipate which symbols will beencountered and manually initialize or change the enabled decoders.These units are often supplied with a default or subset of the totalavailable decoders enabled. This default set is selected in an attemptto optimize the operating speed of the device by disabling similar butdifferent decoding algorithms that when enabled, often result in latencyin the decoding operation or the perception of “sluggishness” by theuser. If the attempted code to be read is not enabled, and the user isnot particularly skilled in determining the actual code or in the use ofthe appliance, the unit will not successfully decode the symbolregardless of the number of attempts. The user will then, most oftenincorrectly, determine something is wrong with the appliance and seekfurther technical support or even attempt to return the device forrepair. This results in considerable operating inefficiency andincreases the total cost of ownership of the appliance due to the lossof productivity and incremental overhead in providing support for whatis a configuration problem.

These units also allow for the operator to select an operating window orfield of view and image capture configuration of the appliance toreflect the use application. This again requires the operator to be ableto determine the field of view or window size that is optimum and thebest image capture configuration to ensure image fidelity. The selectionof these parameters has a significant effect on both the time requiredto capture and process an image, as well as image fidelity.

Therefore there is a need for a self-optimizing symbology reader whichdoes not require operator intervention in order to configure the decodeparameters for maximum productivity.

SUMMARY OF THE INVENTION

The present invention is directed to a method for optimizing a symbologyreader having activated decode algorithms. The method comprises scanninga succession of symbols, decoding the scanned symbols, trackingsuccessfully decoded symbols, identifying a symbol type from among thesuccession of successfully decoded symbols, and disabling all decodealgorithms not used to decode the identified symbol type.

In accordance with a further aspect of this invention the methodcomprises scanning a succession of symbols, decoding the scannedsymbols, storing symbol type information, counting the number ofsuccessively decoded symbols, identifying a symbol type from among thenumber of successively decoded symbols, and disabling all decodealgorithms not used to decode the identified symbol type.

In accordance with a specific aspect of this invention, the method maycomprise identifying the size of the identified symbol type andadjusting the symbology reader window size and/or identifying imagecapture parameters and adjusting the symbology reader image captureparameters.

In accordance with another aspect of the invention, the method comprisesretrieving a pixel per element count from the scanned symbol, reducingthe symbology reader integration time and gain when the count is below apredetermined threshold level, and increasing the symbology readerintegration time and gain when the count is above a predeterminedthreshold level.

Further, the present invention is directed to system for optimizing asymbology reader having activated decode algorithms. The systemcomprises a scanner for scanning a succession of symbols, a decoder fordecoding the scanned symbols, a tracker for tracking successfullydecoded symbols, an element for identifying a symbol type from among thesuccession of successfully decoded symbols, and a control for disablingall decode algorithms not used to decode the identified symbol type.

In accordance with a further aspect of this invention the systemcomprises a scanner for scanning a succession of symbols, a decoder fordecoding the scanned symbols, a memory for storing symbol typeinformation, a counter for counting the number of successively decodedsymbols, an element for identifying a symbol type from among the numberof successively decoded symbols, and a control for disabling all decodealgorithms not used to decode the identified symbol type.

In accordance with a specific aspect of this invention, the system maycomprise a unit for identifying the size of the identified symbol type,and a control for adjusting the symbology reader window size, and/or aunit for identifying image capture parameters, and a control foradjusting the symbology reader image capture parameters.

In accordance with another aspect of this invention, the systemcomprises a counter for retrieving a pixel per element count from thescanned symbol, a control for reducing the symbology reader integrationtime and gain when the count is below a predetermined threshold level,and a control for increasing the symbology reader integration time andgain when the count is above a predetermined threshold level.

In accordance with a further aspect of the invention, the systemincludes a control for resetting the symbology reader defaults.

In accordance with another specific aspect of the invention, the symboltype is a specific symbol.

Other aspects and advantages of the invention, as well as the structureand operation of various embodiments of the invention, will becomeapparent to those ordinarily skilled in the art upon review of thefollowing description of the invention in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein:

FIG. 1 is a schematic representation of a symbology reader in accordancewith an embodiment of the present invention.

FIG. 2 is a flow chart illustrating the basic steps of the method inaccordance with an embodiment of the present invention FIG. 3 is apartial flow chart illustrating the method of the embodiment describedin FIG. 2.

FIG. 4 is a flow chart illustrating the basic steps of the method inaccordance with another embodiment of the present invention.

FIG. 5 is a partial flow chart describing the method of the embodimentdescribed in FIG. 4.

FIG. 6 is a schematic representation of the scanning window size optionsin accordance with an embodiment of the present invention.

FIG. 7 is a flow chart illustrating the basic steps of the method inaccordance with an embodiment of the present invention FIG. 8 is apartial flow chart depicting the method of the embodiment described inFIG. 7.

FIG. 9 is a partial flow chart depicting a step to set the image captureparameters in an embodiment of the present invention.

DETAILED DESCRIPTION

For purposes of explanation, specific embodiments are set forth toprovide a thorough understanding of the present invention. However, itwill be understood by one skilled in the art, that the invention may bepracticed without these specific details. Moreover, well-known elements,devices, process steps and the like are not set forth in detail in orderto avoid obscuring the scope of the invention described.

In symbology readers, including scanner and image based readers, theinvention provides methods for optimizing configuration parameters withlimited need for operator intervention.

The method of self-optimization, in accordance with the presentinvention, may be implemented by the system shown in FIG. 1. An imagebased symbology reader 1 in accordance with the present inventioncomprises a microprocessor 2 that controls all aspects of the imagecapture, analysis, decoding and external host interface, and utilizesoperating software stored in nonvolatile memory 4 and a self-optimizingalgorithm also stored in memory 4. Reader 1 further includes an imagestorage 6 and an image sensor interface 8. The image sensor 10 may beeither CMOS or CCD. An objective lens 12 is positioned in front of theimage sensor 10 to direct the image of the target 14 onto the imagesensor 10. Memory 5 receives the image from the image sensor 10 andstores it for the image process and analysis routine. This image is alsoavailable for transport to an external source as a picture of the sceneor object of interest. An illumination system for lighting the target 14comprises illumination drivers 16 and an illumination source 18, whichusually includes light emitting diodes (LED's).

A basic self-optimizing mode of operation of reader 1 is illustrated inFIG. 2. A symbology is scanned (or imaged) 20 and decoded 22. Each timethe symbology reader performs a decode sequence, information about thatdecode sequence is tracked and written to memory 24. A series ofsuccessful and successive decode cycles are detected representing asequence of identical symbology types, and a symbology of interest isidentified 26. Next, all unused decode algorithms are disabled 28,leaving only the decode algorithm relating to the symbology of interest.

Initially, the default settings reset after a predetermined number ofunsuccessful or unsuccessive decodes takes place. For example thesymbology reader may automatically reset the default settings after fouror five failed decodes. They may also be reset by a trigger routineactivated by the human operator. A trigger routine for example, mayrequire that a human operator activate the trigger mechanism used forinitiating a decoding sequence three times in a row, or alternatively,holding down the trigger mechanism for a number of seconds. In anotherembodiment, after a predetermined number of unsuccessful or unsuccessivedecodes takes place, the user may scan what is typically known as aconfiguration barcode to reset the operating system parameters to adefault condition.

Once the unused decode algorithms have been disabled, any subsequentsymbology which is different from the symbology of interest will resultin a failed decode attempt. After a predefined number of failed attemptsto decode this symbology, the reader will default to the full range ofdecoders. For example, if the symbology of interest is PDF417 and thenext symbol to be scanned is a Code 39 symbol, then the decode attemptwill fail. At this point a human operator could trigger a reset, or thereader 1 would reset the decoders once a predefined number of faileddecodes had taken place.

These steps are described in further detail with reference to theflowchart of FIG. 3. The symbology reader 1 of the present invention isprogrammed with a selectable, self-optimizing mode 30. The mode may beselected by a trigger mechanism of some kind, or as a menu option on thedevice interface. Once the self-optimizing mode 30 is selected, thesymbology reader 1 is capable of auto-discriminating between varioustypes of standard symbologies, usually one-dimensional ortwo-dimensional barcodes, but also encompassing postal or opticalcharacter symbols.

When a symbology is scanned 32 and decoded 34, information that iscaptured in memory 40 includes the symbology type, e.g. Code 39 or PDF417, and in the case of image based symbology readers 1, may alsoinclude the physical size of the symbology as determined by the portionof the image sensor array occupied by the symbol, and the number ofpixels per feature occupied by the barcode elements. Once theself-optimizing mode has been selected, the self-optimizing algorithmtracks the number of decoding attempts 36 made by the symbology reader1. A query 38 determines if the decode is successful. If it is, the datais output 42 and the information is passed on to the next query 44. Atquery 36 the number of decode attempts are tracked and if a predefinednumber of decodes are unsuccessful, the symbology reader resets thedefaults 52 if necessary.

At query 44 the successful decodes are tracked and if the predefinednumber of successful decodes are not reached, the algorithm retrievesthe next symbol to be scanned 46. If the predefined number of successfuldecodes are reached, then the next query in the algorithm determineswhether these decodes are successive 48, i.e whether the decodedsymbologies are sequentially the same type of symbology? If they arenot, the next symbol is scanned 46, however, if they are successive, thealgorithm disables all unused decode algorithms 50. For example, ifafter five successful decodes it was determined that all decodesutilized the PDF417 decode routine, all other decoding algorithms, withthe exception of the PDF417 algorithms, would be disabled. The reader 1then continues to scan and decode subsequent PDF417 symbologies.

Once the unused decoders are disabled, and a new symbol of a type otherthan the selected symbology of interest is to be decoded, then theunused decoders may be reset in one of two ways. Either the humanoperator could activate the trigger routine to reset the defaults, orthe self-optimizing algorithm would automatically reset the disableddecoders, since the new symbology type would generate failed decodeattempts.

In an alternative embodiment of the present invention, a grouping ofrelated symbologies may also be selected in the same manner as above.For example, if the symbology of interest were identified as a Code 39barcode, which is used in industrial applications, the self-optimizingalgorithm would disable all other groupings of symbologies with theexception of the decoder grouping pertaining to similar industrialsymbologies. The industrial symbology decoder group may includeInterleaved 2 of 5, Codabar and Code 128 as well as Code 39 symbologies.By identifying just one of these codes as the symbology of interest, theentire group of symbologies remains enabled in the reader. This may beuseful in situations where a number of similar and related symbologieswill be used repeatedly. These groupings of decode algorithms couldrelate to a variety of applications including retail, postal andindustrial symbologies or it could include combinations of these andother applications. These groups may be user-definable within the hostinterface as a user option symbol grouping mode. The user can select anycombination of available codes to reflect the operation at hand.

Another embodiment of the present invention, is illustrated in FIGS. 4and 5 and relates generally to image-based symbology readers. While mostof the steps in the self-optimizing mode remain unchanged from theembodiment above illustrated in FIG. 3, a step may be added whereby thefield of view (FOV) of an image-based symbology reader can be changed byadjusting the scanning window size 54 to accommodate the symbology ofinterest. When the self-optimizing mode is activated, a symbology isscanned (imaged) 20 and decoded 22. Each time the symbology readerperforms a decode sequence, information about that decode sequence istracked and written to memory 24. Additionally, in this embodiment,information pertaining to the size and aspect ratio of the symbology 53is also tracked. Once the symbology of interest has been identified 26,all unused decode algorithms are disabled 28, leaving only the decodealgorithm relating to the symbology of interest and the scanning windowsize is adjusted 54 thereby changing the FOV to accommodate thesymbology of interest.

The scanning window represents the pixels in the image sensor arraywhich are actually read during each cycle. Narrowing the FOVsignificantly reduces the time required to complete a decode cycle. Bycapturing the actual size and aspect ratio of a series of successivelydecoded symbologies, as well as the symbology type, in memory 40, thesymbology reader of the present invention can self-adjust its scanningwindow 54 to accommodate the symbology of interest.

A representation of the multiple scanning window sizes of the reader ofthe present invention is detailed in FIG. 6. For example, if theoperator continually scans a UPC barcode 75, a code which is relativelysmall compared to the default field of view 60 of a typical image basedreader, and has a roughly symmetrical aspect ratio, then the symbologyreader would adjust the scanning window 85 down to a reduced size 65 or70 that allows for a higher read rate but minimizes both scan, readoutand symbology detection time by removing the unnecessary backgroundinformation. Further, by reducing the window size 85, the number ofpartial decode errors caused by nearby symbols 80 within the default FOVis reduced since these symbologies would, in effect, be cropped from theFOV by the reduced scanning window sizes 65, 70.

The scanning window size 85 may be an adjustable parameter that isdefined when the symbology reader is first programmed. The window size85 could be selectable in a number of multiples of the size of thesymbol dependent upon trading off aiming latitude, i.e. the breadth ofaiming range, versus read rate. The window size 85 could be adjusted totwo, three or four times the size of the symbology 75 for example.Larger multiples provide greater user latitude but increase the time toperform the decode sequence.

The scanning window 85 may be reset to the default FOV setting 60 by thealgorithm in conjunction with the decode algorithms defaults being reset52, either after a number of unsuccessful decodes, or after thetriggering routine activated by a human operator, as described above.

In an alternative embodiment, the scanning window 85 may be resetindependently of the decode default reset as described above. It may bereset by activating a unique trigger routine, for example, which resetsonly the scanning window size 85 back to the default FOV setting 60.

Another embodiment of the present invention is illustrated in FIGS. 7and 8 and relates generally to image-based symbology readers. While mostof the steps in the self-optimizing mode remain unchanged from theembodiments described above with regard to FIGS. 3 and 5, a new imagecapture step is added, in image-based symbology readers, in which theimage capture parameters are set 100 after the symbology of interest hasbeen identified. Adjusting the image capture parameters maximizes therobustness of reading of the symbology of interest. When theself-optimizing mode is activated, a symbology is scanned 20 and decoded22. Each time the symbology reader performs a decode sequence,information about that decode sequence is tracked and written to memory24. Identification of the symbology of interest 26 as well as the sizeof the symbology of interest 53 is extracted from the decodeinformation. Additionally, in this embodiment, image capture informationpertaining to the number of pixels per element 90 of the symbology ofinterest is also tracked. The unused algorithms are then disabled 28 andthe scanning window size 54 and image capture parameters 100 may beadjusted as needed depending of the feature size of the symbology ofinterest.

The step of setting the image capture parameters 100 within theself-optimizing mode is described in more detail with reference to thepartial flowcharts of FIG. 9. The pixel per element count information istracked and identified 94 and compared to a threshold value stored inmemory. This threshold would likely be a small, predefined range ofvalues representing the optimum pixel count per symbology element,corresponding to the default image parameter setting. If it is foundthat the number of pixels per element is small 96 compared to thethreshold, leading to the potential for misreads as the number of imagedpixels per element or feature may be at the limit of the decoderalgorithm or be affected by the image capture parameters of the imagereader, the system would anticipate that the feature size of the printedsymbol is also small and therefore the system would optimize the imagecapture parameters by reducing integration (exposure) time and digitalimage sensor gain 102. The reduction of integration time minimizes imageblue induced by operator hand movement or jitter, while the reduction ofgain reduces image noise that could result in a decode failure. Thiswould typically be encountered in direct part mark reading applicationswhere the code feature size must be quite small due to the limited areafor code location on the marked parts.

Conversely, if the number of pixels per element were found to be verylarge 98, the system could anticipate that the feature size is quitelarge and would adjust the image capture parameters by increasing theintegration or exposure time and digital image sensor gain 106. Thiseffectively increases the depth of reading of the device, providing theuser with more latitude in selecting a distance from which the symbologyof interest would be readable. An example of this application would bewarehousing operations which traditionally employ very large featuresize symbols on large objects such as pallets or packages.

If the number of pixels per element is found to be acceptable, beingwithin the threshold range, the default image capture parameters 104remain unchanged for the next scan 46 and decode sequence. However, ifthe image capture parameters are adjusted 102 or 106, the next scan 46and decode sequence will be performed with the newly optimized settings.

An advantage to disabling the decode algorithms not being used,adjusting the scanning window size and/or image capture parameters isimproved symbology reader performance caused by increased speed ofdecoding, the elimination of unnecessary background information and/oroptimized image capture. This is especially useful in settings where thesame type of symbology with the same size parameters are used all thetime or a series of similar symbologies are used repeatedly. Thedisabling of all unused algorithms minimizes the possibility ofsymbology recognition errors. Further, this method does not require userintervention in setting symbology decode type, scanning window size orimage capture parameters.

While the invention has been described according to what is presentlyconsidered to be the most practical and preferred embodiments, it mustbe understood that the invention is not limited to the disclosedembodiments. Those ordinarily skilled in the art will understand thatvarious modifications and equivalent structures and functions may bemade without departing from the spirit and scope of the invention asdefined in the claims. Therefore, the invention as defined in theclaims, must be accorded the broadest possible interpretation so as toencompass all such modifications and equivalent structures andfunctions.

1. A method for optimizing a symbology reader having activated decodealgorithms in storage comprising: scanning a succession of symbols;decoding the scanned symbols; tracking successfully decoded symbols;identifying a symbol type from among the succession of successfullydecoded symbols; and disabling all decode algorithms not used to decodethe identified symbol type.
 2. A method as claimed in claim 1 whereinthe symbol type is a specific symbol.
 3. A method as claimed in claim 1comprising: identifying the size of the identified symbol type; andadjusting the symbology reader window size.
 4. A method as claimed inclaim 1 comprising: identifying image capture parameters; and adjustingthe symbology reader image capture parameters.
 5. A method as claimed inclaim 1 comprising: retrieving a pixel per element count from thescanned symbol; reducing the symbology reader integration time and gainwhen the count is below a predetermined threshold level; and increasingthe symbology reader integration time and gain when the count is above apredetermined threshold level.
 6. A method for optimizing a symbologyreader having activated decode algorithms in storage comprising:scanning a succession of symbols; decoding the scanned symbols; storingsymbol type information; counting the number of successively decodedsymbols; identifying a symbol type from among the number of successivelydecoded symbols; and disabling all decode algorithms not used to decodethe identified symbol type.
 7. A method as claimed in claim 6 whereinthe symbol type is a specific symbol.
 8. A method as claimed in claim 6comprising: identifying the size of the identified symbol type; andadjusting the symbology reader window size.
 9. A method as claimed inclaim 6 comprising: identifying image capture parameters; and adjustingthe symbology reader image capture parameters.
 10. A method as claimedin claim 6 comprising: retrieving a pixel per element count from thescanned symbol; reducing the symbology reader integration time and gainwhen the count is below a predetermined threshold level; and increasingthe symbology reader integration time and gain when the count is above apredetermined threshold level.
 11. A system for optimizing a symbologyreader having activated decode algorithms in storage comprising: ascanner for scanning a succession of symbols; a decoder for decoding thescanned symbols; a tracker for tracking successfully decoded symbols;means for identifying a symbol type from among the succession ofsuccessfully decoded symbols; and a control for disabling all decodealgorithms not used to decode the identified symbol type.
 12. A systemas claimed in claim 111 wherein the symbol type is a specific symbol.13. A system as claimed in claim 11 comprising: means for identifyingthe size of the identified symbol type; and a control for adjusting thesymbology reader window size.
 14. A system as claimed in claim 11comprising: means for identifying image capture parameters; and acontrol for adjusting the symbology reader image capture parameters. 15.A system as claimed in claim 11 comprising: a counter for retrieving apixel per element count from the scanned symbol; a control for reducingthe symbology reader integration time and gain when the count is below apredetermined threshold level; and a control for increasing thesymbology reader integration time and gain when the count is above apredetermined threshold level.
 16. A system for optimizing a symbologyreader having activated decode algorithms in storage comprising: ascanner for scanning a succession of symbols; a decoder for decoding thescanned symbols; a memory for storing symbol type information; a counterfor counting the number of successively decoded symbols; means foridentifying a symbol type from among the number of successively decodedsymbols; and a control for disabling all decode algorithms not used todecode the identified symbol type.
 17. A system as claimed in claim 16wherein the symbol type is a specific symbol.
 18. A system as claimed inclaim 16 comprising: means for identifying the size of the identifiedsymbol type; and a control for adjusting the symbology reader windowsize.
 19. A system as claimed in claim 16 comprising: means foridentifying image capture parameters; and a control for adjusting thesymbology reader image capture parameters.
 20. A system as claimed inclaim 16 comprising: a counter for retrieving a pixel per element countfrom the scanned symbol; a control for reducing the symbology readerintegration time and gain when the count is below a predeterminedthreshold level; and a control for increasing the symbology readerintegration time and gain when the count is above a predeterminedthreshold level.
 21. A system as claimed in claim 16 comprising: acontrol for resetting the symbology reader defaults.